Prevalence and distribution of dermatophytosis lesions on cattle in Plateau State, Nigeria.

BACKGROUND AND AIM: Dermatophytosis is an infection of the superficial, keratinized structures of the skin, nails, and hair of man and animals caused by a group of fungi called dermatophytes in the genera Trichophyton, Microsporum, and Epidermophyton. The prevalence of dermatophytosis among cattle in Nigeria and Plateau State, in particular, is yet to be fully determined. This study aimed to determine the prevalence and the distribution of dermatophytosis lesions on cattle in Plateau State, Nigeria. MATERIALS AND METHODS: Four hundred and thirty-seven cattle showing visible skin lesions suggestive of dermatophytosis were drawn from nine local government areas (three each) from the three senatorial districts of Plateau State, Nigeria. Skin scrapings were aseptically collected using a cross-sectional study, in which sampling units were selected using purposive sampling method. Samples were processed for both direct microscopic examination and isolation of dermatophytes in culture. The isolates were stained with lactophenol cotton blue and identified microscopically based on the size, shape, and arrangement of macro- and micro-conidia. The dermatophytes were further identified by determining the sequences of the internal transcribed spacer regions of their ribosomal DNA. Data were analyzed and presented as percentages, bar graph, and Chi-square test of association. p≤0.05 was considered statistically significant. RESULTS: The overall prevalence rate of bovine dermatophytosis in Plateau State was found to be 11.0%. Trichophyton verrucosum was more frequently isolated (54.2%) than Trichophyton mentagrophytes (45.8%). Age, breed, management practice, and season were significantly associated with the occurrence of the disease (p<0.05). CONCLUSION: Dermatophytosis among cattle may be of public health significance in Plateau State, Nigeria. This is the first report on the prevalence and distribution of dermatophytosis lesions on cattle from Plateau State, Nigeria.

A risk assessment study of the occurrence and distribution of aflatoxigenic Aspergillus flavus and aflatoxin B1 in dairy cattle feeds in a central northern state, Nigeria.

Nigeria, being a tropical nation, characterized by favorable climatic conditions, may display high chances of feed contaminations due to aflatoxigenic Aspergillus flavus with the consequences of health risks associated with the consumption of dairy products. A cross-sectional study was conducted to examine the risks of occurrence and distribution of aflatoxigenic Aspergillus flavus (A. flavus) and aflatoxin B1 (AFB1) contamination levels based on the European Union (EU) and United States Food and Drug Administration (USFDA) set limits. Feeds (n = 144) were collected from selected conventional and traditional dairy herds; prepared and analyzed using immuno-affinity column (IAC) and high performance liquid chromatography (HPLC) respectively. Forty eight (55.8%) isolates were identified as A. flavus of the isolated Aspergilli (n = 86). Of this proportion, 12 (25.0%) were aflatoxigenic strains. An outrageous number of the tested feeds (86.8%, n = 144) were positive for AFB1 contamination. Detectable AFB1 concentrations ranged between (0.5 and 24.8) µgKg-1 and were distributed variously according to many factors of distribution. Eighty three (66.4%, n = 125) of the AFB1 contaminated feed samples showed AFB1 concentrations between 5 and ≥20 µgKg-1. All-inclusive policies are key to reducing the health risks posed to the consumers of dairy products.

Severe generalized skin lesions due to mixed infection with Sporothrix schenkii and Dermatophilus congolensis in a bull from Jos, Nigeria.

Sporothrix schenkii and Dermatophilus congolensis were isolated from a bull with severe generalized skin lesions. The lesions were thick, crusty and scabby on the dorsal part while few scabby and several nodular lesions were seen on the lower limbs especially the thighs. Scab samples and exudates from the nodules were aseptically collected and processed for bacteriology and mycology. Gram stained smears revealed Gram-positive, filamentous organism that had longitudinal and transverse septa suggestive of D. congolensis. Colonies on 5% defibrinated sheep blood agar were small, rough, grayish-white, ß-hemolytic and adherent to the medium. It was catalase positive, urease positive and fermented glucose and maltose but not sucrose, lactose, mannitol, sorbitol and xylose. Colonies on Sabouraud's dextrose agar were small, round, white and opaque, delicate and smooth. It liquefied gelatin and fermented glucose and sucrose but not galactose, menite, and glycerin. The isolate was Gram-positive, cigar-shaped and yeast-like suggestive of S. schenkii. Dermatophilosis is common in domesticated ruminants while sporotrichosis is very rare in cattle. This may be the first report of bovine sporotrichosis from Africa.

Erythrocyte sialic acid in human sickle-cell disease.

Membrane-bound erythrocyte surface sialic acid concentrations in sickle-cell human patients (SS) and in control patients with sickle-cell trait (AS) and normal genes (AA) were assayed. The erythrocyte sialic acid concentration was significantly (P less than 0.001) higher in sickle-cell patients than in non-sicklers and although the concentration was higher in AS than AA individuals the difference was not significant (P greater than 0.05). The anaemic state of the SS patients was shown by a significantly (P less than 0.001) lower PCV than in non-sicklers. This finding is discussed in relation to membrane toughness and subsequent membrane loss leading to irreversible sickling of red cells in the deoxygenated state.